Abstract
Sound source discrimination was evaluated by sound localization performance and event-related potentials (ERP) with normal subjects using two sound sources in a dark semi-anechoic room. Non-target and target noise burst stimuli were presented by a loudspeaker in front of the subject and a lateral one, respectively. The angle between the two loudspeakers was set between 2.4 and 27.6 degrees. Localization performance were measured by the changes in direction of face from non-target loudspeaker toward target one by using an electromagnetic tracking instrument. ERP were measured by oddball test with the same acoustic stimulating system. The localization performance showed the changes in face angle were rather accurate to point loudspeaker locations. The amplitude of the ERP components that were different between target and non-target ERP were measured as a function of the angle between two speakers. The peak-to-peak amplitude between negative wave with the latency of about 150ms and positive waves with the latency of about 250ms increased as the degree of angle between two loudspeakers increased. The relationship between performance angles and difference ERP amplitude was proportional. These results indicate that the ERP represents the perception of the angles of the two sound sources. [Jpn J Physiol 54 Suppl:S168 (2004)]
